function checkIdCard( idCardNumber ) {
	if ( !idCardNumber || typeof idCardNumber !== 'string' || idCardNumber.length !== 18 )
	return false

	const coefficient = [ 7, 9, 10, 5, 8, 4, 2, 1, 6, 3, 7, 9, 10, 5, 8, 4, 2 ]
	const checkCode = [ 1, 0, 'x', 9, 8, 7, 6, 5, 4, 3, 2 ]
	const code = idCardNumber.substring( 17 )

	let sum = 0
	for ( let i = 0; i < 17; i++ ) {
		sum += Number( idCardNumber.charAt( i ) ) * coefficient[ i ]
	}

	return checkCode[ sum % 11 ].toString( ) === code.toLowerCase( )
}

export default checkIdCard